Analyzing Ducati's Aero Attachments: Four Factories Protest, But Are They Legal?

Submitted by David Emmett on Mon, 2019-03-11 18:18

Andrea Dovizioso's victory in the opening race of the 2019 MotoGP season at Qatar is currently subject to appeal. Dovizioso raced in Qatar using the aerodynamic components previously debuted by factory Ducati teammate Danilo Petrucci at the Qatar test, and used by Petrucci and Pramac Ducati's Jack Miller during practice at the Qatar MotoGP round.

After Dovizioso won a thrilling, close race by a margin of 0.023 seconds from Marc Márquez, the top five finishing with six tenths of a second, but the race was the first time Dovizioso had used the new aero parts. That prompted four factories – Aprilia, Honda, KTM, and Suzuki – to lodge a protest with the FIM Stewards, claiming that the aerodynamic device attached to the swingarm (see the tweet from MotoMatters.com contributor Tom Morsellino below) is illegal.

After conferring with the Technical Director Danny Aldridge, the FIM Stewards rejected the protest by the four factories, on the grounds that the aerodynamic devices used did not contravene the regulations. The four factories then immediately lodged a protest, which they had prepared previously. According to Manuel Pecino, writing in the Spanish daily Mundo Deportivo, the parties involved had signaled in advance that they would be protesting Ducati's use of the devices, if they were used in the race.

The appeal will now go forward to the MotoGP Court of Appeals, which will meet in Geneva, where they will consider the case. A judgment is expected to take a couple of weeks, and may not be ready before the next round of MotoGP at Termas de Rio Hondo in Argentina. The results of the Qatar round of MotoGP will stand unless they are overturned by the Court of Appeal, although if they are overturned, and Ducati's aero devices ruled illegal, Ducati are certain to appeal to the Court of Arbitration for Sport (CAS). If the Court of Appeal upholds the ruling of the FIM Stewards, then that will settle the matter once and for all. No right of further appeal exists in that case.

The letter of the law

Speaking on Sunday night, Ducati Corse Sporting Director Paolo Ciabatti explained why Ducati believed the aero devices are legal. "It should be clear to everyone, because all manufacturers received a document from Danny [Aldridge] on the 2nd of March, which was guidelines for aerodynamics in general, mainly due to the bodywork," he said.

"But it had a specific article related to that, saying that you can use [such parts] under certain limits: it has to be attached to the swing arm, it has to move with the swing arm, it has to be used for cooling, protecting from water, protecting the rear wheel from debris. We use it for cooling," Ciabatti said.

This directly contradicted Danilo Petrucci, who told us on Friday, "We saw on television that it was for cooling down the rear tire but it is not like this. But I can’t tell you what it is for, because Gigi will get angry."

Ciabatti said that Ducati had not wanted anyone to know that the purpose of the aero device was cooling, for the same reason they don't tell anyone about what any of the rest of the bike does. "We didn't like to say this, because we don't like to tell people what we are doing," Ducati's Sporting Director said. "But that's the main purpose. Its purpose is not to create an aerodynamic force to the ground, which is what they say. And ours is not for that."

Why so late?

What Ciabatti objected to was the fact that the other factories had had eight days to either object, or to ask for clarification from Technical Director Danny Aldridge, but had waited until the race to do so. "So everybody has had this for eight days, since Saturday last week. I think in principle, at least, my idea is that if you receive something from the Technical Director of the championship, and you don't agree or you have doubts, you write back, saying 'this is not good, this is not clear, we don't agree, we think it's not specifying enough because people might be cheating, and so on'. Nobody did that. And I hope everybody read it. So what can I say more?"

There were avenues which the other factories could have explored, Ciabatti pointed out. "I think everybody read [the directive]. But when you read it, why don't you do the normal thing? We have the MSMA on one side, we have Danny, who is always available to answer. Just having eight days and then waiting to answer, is questionable."

Ciabatti pointed out that that Dovizioso's winning margin was still very tight, and with Danilo Petrucci finishing sixth, the difference these aero devices were making was very small. "Dovi won by 23 thousandths of a second," he said. "When you are competing at this level, and you are competing against Honda, and against Márquez, who as we know is an exceptional rider, every fraction of second, every fraction of a hundredth of a second counts. So if we have something that is legal, and can give – obviously, for riders who are wearing more the rear tires like Danilo and Jack, it's probably more useful in general – but if you think it is a fraction of a fraction of a millisecond advantage to Andrea on saving the tire for the last part of the race, why not, if it's legal?"

The MotoGP Aero Body is defined as the portion of the motorcycle bodywork that is directly impacted by the airflow while the motorcycle is moving forward, and is not in the wake (i.e. aerodynamic “shadow”) of the rider’s body or any other motorcycle body parts. Therefore the Aero Body consists of the two separate components Front Fairing and Front Fender (Mudguard), as per the diagrams the Appendix, General:Fig.5, Fig.6.

To make the rules clear, the rule book also has a diagram:

If you compare this with Tom Morsellino's photo included above, you can clearly see that Ducati have looked at the diagram and seen where the loophole was. They applied the covers to the bottom of the front wheel, and attached a spoiler to the bottom of the swingarm. For the latter part, they may have been inspired by Yamaha's rain deflector which made its debut last year (shown below, again in a photo by Tom Morsellino).

As these parts are not attached to what the rules call the Aero Body (the fairing and front fender), Ducati are free to attach and remove them as they see fit. This is why they do not fall under the ban on detachable aerodynamic parts, as set out in the rules.

Publish the guidelines

Although the parts are legal under the FIM regulations as published, there is one key piece of information missing. The additional guidelines sent to the factories on 2nd March, and before that in February, are not available on the FIM website. But Paolo Ciabatti told us that it included a section explicitly allowing attachments to the swingarm, as long as such an attachment did not create downforce, but was used for either cooling or for deflecting water or debris.

The other manufacturers are claiming that this is where Ducati is breaking the rules. They do not believe that the rear spoiler – which is the part they are protesting against – is being used for cooling. According to Aprilia CEO Massimo Rivola, speaking to Italian website GPOne.com, the CFD (computational fluid dynamics) simulations they had run showed that the rear spoiler was generating downforce on the rear wheel, something which is explicitly banned, according to the guidelines issued by Danny Aldridge. They showed Aldridge the simulation data, which showed the airflow over the rear spoiler.

But even then, Rivola doesn't believe that it should be up to Aprilia or rival manufacturers to prove that the Ducati spoilers are not legal, but up to Ducati to prove with data that their parts are not violating the rules. "There are three wings on the inside of the spoiler, the classic tri-plane configuration. Why did they need three wings?" Rivola asked rhetorically.

Is cooling necessary?

Rivola was skeptical of Ducati's claims that the spoiler is for cooling the tire. Sure, he told GPOne.com, it made sense if the device was only fitted to the bikes of Danilo Petrucci and Jack Miller, both of whom are known to be very heavy on tire consumption, not least because Petrucci is one of the heaviest riders on the grid.

But temperatures at Qatar were very low this year, and Andrea Dovizioso is 11 kg lighter than his teammate. Why would Ducati fit the spoilers to Dovizioso's bike? What's more, Dovizioso elected to use the medium rear tire, which theoretically should have less risk of overheating.

On the other hand, Ducati and Gigi Dall'Igna have made no secret of their focus on tire management as a way of using the excessive horsepower which the Desmosedici engine produces, without chewing up the rear tire halfway through the race.

Effective

That the rear spoiler has some form of aerodynamic effect is obvious, if only for the fact that it is only ever used in conjunction with the front wheel covers. However, whether the rear spoiler creates downforce or not is hard to see without seeing a simulation, or the bike in a wind tunnel. Ex-Moto2 crew chief Peter Bom believes the parts work together to reduce turbulence and smooth the airflow. The front wheel covers smooth the air going onto the bottom half of the fairing.

The big question is what happens to that smooth (or laminar) airflow when it hits the rear spoiler. It is possible that the flow is more efficient in cooling the rear tire. It is also possible that it is generating more downforce on the rear wheel through the swingarm. Or, as MotoMatters.com reader and engineer Andrew Gregory suggested to me by email, it could be acting as a venturi, to prevent the laminar flow on the underside of the fairing from slamming into the wall of turbulent air caused by the rotation of the rear wheel, thereby reducing drag.

Would that be a violation of the rules? Without being able to see the guidelines issued to the factories, it is impossible to say. If the guidelines specify that only devices creating downforce are banned, and the Ducati spoiler would be legal if it cooled the tire or reduced turbulence. If the guidelines say that devices may not create an aerodynamic effect, then Ducati's spoiler would contravene the rules.

Money pit

The real reason for the complaints is to try to rein in Ducati's creativity with the aerodynamic regulations, something which Gigi Dall'Igna complained about at the Ducati launch. Aerodynamics is an area, like electronics, where factories can find incremental gains by throwing more resources at a project. That can quickly allow costs to spiral out of control.

The protest of the four factories was not aimed at Andrea Dovizioso, KTM's Pit Beirer told German-language website Speedweek. "Hopefully Dovi won't have this victory taken away from him," Beirer said. "He deserved this win. And so did Ducati, with the technical achievements. But we want clarity for the future, otherwise we will have wings sprouting everywhere. We want to make sure that these kinds of aerodynamic excesses are limited in the future."

Ducati opened a Pandora's box when they reintroduced wings after the adoption of the spec software, as an ingenious solution to countering wheelies using airflow instead of ECU software algorithms. Once the engineers were given that avenue to explore, they have found all sorts of fresh innovations and advantages. The current MotoGP regulations were not written with aerodynamics in mind. As usual, the engineers have spotted a loophole, and driven a coach and horses – or rather, a fleet of race trucks – through it.

The Dorna press release announcing the appeal to the MotoGP Court of Appeal appears below:

The protests were made by Aprilia Racing Team Gresini, Red Bull KTM Factory Racing, Repsol Honda Team and Team Suzuki Ecstar, who presented their concerns to the FIM MotoGP Stewards Panel. Based on guidelines and regulations currently in force, the FIM MotoGP Stewards Panel rejected their protests.

An appeals process then began and the appeals panel has subsequently decided to refer the case to the MotoGP Court of Appeals in order to attain more information pertaining to the matter.

Comments

Petrucci may have screwed them by letting it slip that it’s not for cooling. I remember hearing years ago that at the Daytona 200, the superbikes has substantial wheelspin at top speed on the banking because they had the torque to spare but didn’t have the traction to use it.

With the manufacturers going for more hp in concert with more drag from the ever-increasing aero devices, is it possible that this is the case presently in MotoGP? That the top speed from 300hp is limited by rear grip since the fairings are ostensibly higher drag now than they were just a few years ago?

Is it possible that running a wing on the swing arm does keep the tire cooler, but not from any cooling effect via airflow, but rather achieving the ridiculous top speed via less wheelspin. If that’s the case it’s totally disingenuous of them to say ‘oops’ and fein ignorance as to how the aero device works...

Given that any rearward force imparted to that swingarm spoiler would get translated into rotational force around the swingarm pivot, I could see where it could generate rear wheel lift, not downforce. Either way it must have some effect. Not sure it meets the letter of: "as long as such an attachment did not create downforce". Seems like a poorly written regulation. As far as the front thingy goes, I for one feel it could be considered a lower extension of the fender and hence subject to regulation. Ultimately, I don't care. My favorite american football team, the Patriots are often accused of cheating when they merely read the rules better than most (most of the time). It seems Ducati has a similar inclination. Kabuki.

the swingarm attachment is directing air upwards into the space between the rear wheel and the swingarm, and probably around the tyre as well. The air direction is upward so the physical effect is to push anything it is attached to downward.

If the device is used as an aerodynamic appendage, and not cooling as Ducati claim, it would have downforce at high speed, pushing the rear tyre into the ground. To be honest though, is hard to see there being too much of an effect, but I would almost hazard a guess that it would help more in preventing wheelies. As the device is attached behind the swingarm pivot and in front of the rear axle, it could help pull the swingarm down, more than just providing rear traction down force.

I still think it would have more of a cooling effect than a downforce one, helping to remove hot air trapped between the swing arm and rear wheel. The rear wheel rotation could be dragging hot air from the back of the engine to behind the swingarm.....

Experimentation, development, pushing the envelope. I think it was HRC that came up with the idea of placing a shroud over the carbon discs to keep the heat in the disc in a wet race. Perhaps it also increased downforce in the wet. Steel discs were abandoned by all for a wet race. No one complained. Rather, they all embraced the idea, eventually. Adapt or die. Aero is here to stay and personally I don't like it anymore than you do. Remember the Guzzi 'dustbin fairing' of yore ? Next step will logically be aero race suits designed specifically around any specific rider's physical aerodynamic profile...and so on it goes. Its already started with aero helmets and lest ye forget, the rider is generally about 30% of the machines aero profile.Cooler tires and warmer discs and, oh wait! warmer tires and cooler discs per event. Too many rules. And lawyers who wrote them making a pile of money arguing the validity of said rules. Nuts!

I did notice that the first thing Alberto Puig did when Marc arrived in parc ferme was have a serious word in his ear and the celebrations started only after they’d exchanged some discreet words. Wonder if he was informing Marc that a protest was under way?

The front "blade" looks to have been so close to the tyre that the Michelin logo has been partially rubbed away. Call me a coward but riding close to 360 kmh with something that looks like an ax made of carbon so close to my tyre.... I dont know if I would have done it...

While all seems like the front element is for aero, thinking further about the rubbing... how about maybe this is the actual purpose: to rub the tyre wall so it creates a support of the tyre wall againt sqeek/deformation during braking or turning. the curvature seems to match the tyre wall and wouldn't necessarily cut into it. Maybe it can support the contact patch of the tyre on the Vertical axis of the tyre.... just wild thinking.

If it's all about aero and directing the airflow caused by the rims towards the rear, we might see the Ducati covered rims on the frontwheel this season.

These are way more effective of directing the air like Formula 1 rim covers back in the day. The challange is the different placement of the front brake disc (next to the fork for aircooling) compared to cars (in the rim). Maybe fully front wheel covered brake ducts in Motogp one day.

Adding a contact to the sidewall of the tyre whilst it's at it's most highly loaded is the stuff of nightmares. If Michelin even suspected that was what Ducati were doing they would have ordered them taken off immediately. A front on photo shows the fairings actually have quite a large amount of clearance over the tyre.

The very best thing Ducati has done for us fans since creating the 916, is hire Gigi Dall'Igna away from Aprilia. I am sure HRC has its geniuses too, but there is nobody like Gigi on the grid. I am also sure he was very upset that his superiors let Lorenzo get away just when he started winning, but Gigi is making Dovi into a genius himself! We can't forget both both HRC and Yamaha discarded Dovi. Yet Gigi turned him into a special racer. The other factories copy Gigi! Even salad boxes for crying out loud! This truly is a golden era for motorcycle grands prix racing. Both in the saddle and in the drafting room. It is a remarkable display of human creativity from the pilot to his supporting cast. It is amazing that old number 46 can still hold his own...

Very difficult that a part with that little surface area, installed in that part of the swingarm will have any significant downforce. Too close to the pivot point. If I was looking for downforce on the rear I would install it either on the axle or behind , to gain as much leverage possible, and then use swept back or delta wings to minimize drag.

On the other hand, if the MotoGP brains are against "Aerodynamics" why aren't they agains "Electronics" in the first place? Let them boys sort out the solutions however they come by, let science follow it's natural evolution path.

with your post entirely. Take my star. Thing is a lot of people don't want to go on that slippery slope. And I see the point too which is contrary to your point. I say remove the electronics. Let the riders dictate what's going to happen. Or else it will be too much like F1 even though I love F1 a lot. I love all the R&D and the innovative solutions and the engineering. Same with these bikes but I think a balanced approach is needed. These appendages make the bikes too ugly.

Not that Gigi & Co are cheating. They are doing what first rate programs do...which is to push the rule envelope as far as possible...knowing it is always easier to ask forgiveness than permission in these matters. But this may be an envelope poke too far, in which case the appropriate response should be "the results stand, take it off by the next race, go forth with our blessing and sin no more". Courts have no role in this, but the technical committes must have the authority to say "enough" with no more justification than the sprit (i.e., intention) of the regulations.

But there has to be a better mechanism than a post race duel "It's handbags at ten paces, gentlemen". From my own perspective, if a bike passes through the scrutineering process it is good to go for that round (understanding that the srutineering process only applies to the visible components, post race tear downs to verify internal compliance are a different matter). Teams should have a way of lodging a legitimate complaint on technical grounds, but at the same time the teams must respect the fact that these are integrated systems, and just unbolting one offending bit Friday afternoon may not be an viable option. Or a fair one. This should all have been hashed out before the first race.

Ducati is definitely the benchmark for aero, and to divert everyone's gaze from the swingarm for a bit, Ducati's use of the high rear exhaust location is brilliant. The considerable energy coming out of that high pipe is fully intergrated with the tailpiece and the "salad box" to have a pronounced positive effect on top speed. I also suspect that the Bollogna aero staff can drive to Maranello with their eyes closed. I find it intersting that the two bikes with the otherwordly top speeds (Ducati and Honda) are using their high-exit exhaust energy in a way not available to the slower bikes (Yamaha and Suzuki). Maybe its not just how hard you press on the wristpins after all.

PS - Nice that Maverick now understands why Vale rides the way he does. It is not the fastest way around an empty track, but it is the mutt's nuts when carving through traffic...and always has been. Wisdom (and race wins) will come Mavericks way when he sorts out that Saturday is not Sunday (and I think he will). Cheers.

I believe the post may have been refering to thrust forces from exhaust which are expanding gasses at high velocity. Ducati has even patented some exahust valve or nozzle recently to enchance this effect. There is also the effect an injection of high velocity gases could have on the surrounding air and the ability to streamline the wake in anyway possible. Not sure how effective that is but comparably it would make more sense that rear exit would smoother than blasting the exhaust straight out the side of the bike, which is more what we see from the others.

This also reminded me of a story about WWII aircraft and the clever use of exahust heat to gain thrust. Famous planes like the P-51 had used the hot gas that came off the radiator and tunneled it throught the body of plane to exit at rear. That plane in particular bears an iconic bottom scope under its fusalage for this purpose. The trick was the heating of the air used to cool the engine in a way that creates an expansion and a small thrust out the back of the plane. That was the theory anyway, and it seemed to work for the fastest and best plane of the day, that was until the advent of the jet engine which took the concept of making thrust from hot expanding exhaust gases to a whole new level :)

Below is a link to read more, while not the exact mechanism involved here it's intresting nontheless, but now that thinking about it,..them Ducati's do run rather hot afterall :)

The exhaust does affect the wake of the air and possibly the drag by narrowing/stretching the movement. The way both exhaust are positioned upwards both cause a downward force on the rear tyre and move the air wake upwards... so possibly reduce the amount of slipstream effect behind it. But this would apply to all V4 bikes on the grid. "Shown with a lighter shade and indicated by the pink arrow marked 'EAB' is the equivalent aerodynamic body . This represents the complete effect that the total body of the motorcycle/rider and the source of mass/momentum (the exhaust) have in the airflow." - Source

If Dorna didn't want an aerodynamic spending war they shouldn't have banned the winglets. They were cheap and worked fine. Just like a double clutch gearbox works fine, but that was banned too and now we have these seamless gearboxes that cost millions to come up with.

I abhor cheating on a racetrack, or in the garage, but if what Ducati has done is not specifically against the rules, then it is legal, no? This protest is little more than sour grapes, yielding a bitter whine. Tip of the hat to Ducati for their careful examination of the rules.

I see "the Scoop", is what I'll call it, doing 3 jobs all in one. I'll keep it simple, First: It will keep the rear wheel on the ground under heavy braking. Second: The airflow will keep the rear cool. Third: The air flow will keep the rear brake cool.

Gigi may be streets ahead of the rest, at this point, with his understanding of the complexities of aero devices and how they behave when subject to different conditions. Just as an example, I think we are reasonably sure that there is an "optimum" operating range for the fairing mounted devices generating downforce, for the sake of simplicity let's say 150-250 KPH. Below that range they have minimal impact...but above that they have too much. I.e., the bloody thing wont turn at very high speeds with the front contact patch smashed into the pavement. This is the nature of most aero devices; they are not linear. Twice the speed doesn't get you twice the force, rather, until the device starts to stall, it is far more of an exponential increase. Which is not at all what we want. And when leaned over the "downforce" is not just pushing down vertically, but also pushing the nose of the bike away from the apex. Which makes us sad.

So perhaps what Ducati has done, with the combination of the front wheel ...uh...spats, and a carefully shaped belly pan, is to introduce a degree of lifting, with these lifting devices effective at a higher speed than the downforce devices. As such they would act to nullify the excess downforce at higher speeds without impacting that downforce in the 150-250 kph range (where they are desirable). The rear "scoop" may be a two-fold device to both aid cooling of the rear tire, and to act as a trim device to restore some additional downforce to the rear wheel (without impacting the lifting effect of the spats and belly pan on the front). Surely, if rear downforce was all that was targeted, any aero device would be mounted much further aft on the swingarm (actually, behind the rear axle), instead of it's current position where, even if it is generating some downforce, it is acting through a much shorter lever arm to the swingarm pivot.

Then again, maybe it is all about turning. A slight lifting at the front (which is really just a reduction of downforce, never approaching a true lifting scenario) combined with an increase at the back would help the bike rotate into the turn when leaned over.

But this is all meaningless conjecture without the data, and until Gigi decides to share that with us (I have the date marked on my calender as "never"), there is really only so much we can glean from staring at shapes. Motorcycle aerodynamics are hellishly complex, as they operate over a significant speed range, with some yaw, a fair amount of pitch, and ridiculous changes in roll. All the time being heavily influenced by ground effects. But what we can know is what a very clever lad like Gigi is after:

To maximize downforce in the critical speed range.

To limit excessive downforce above that speed range, possibly with differing limits at either end of the bike.

To have the aero devices aid turning (if possible), or at least minimize their negative impact on turning.

To utilize the exhaust energy, high and low, to help fill some low pressure areas and optimize pressure recovery in the bike's wake to reduce induced drag.

So, the sad truth of it is this; I really have no idea exactly what Gigi is doing...but every time he changes something I tend to think he is going after one of these objectives...or any of 20 others I am too dimwitted to imagine. Cheers.

not only was that thought provoking it was also highly entertaining "marked in my calander as.... never" made me laugh so much my coffee come out my nose. Looking forward to your next post, no pressure but do let's try, eh? :-)

Having the blades so far ahead of the axle is like putting the rear wing of an F1 car over the cockit rather than behind the rear wheels. The leverage ratio is inverted, so whatever force is generated only a fraction of it is actually seen where it is needed.

But the aero drag of the scoop, looks like a much more effective lever on the swingarm, because it is so far from the line drawn between the axle and swingarm pivot, so it is a much more favourable leverage ratio. Basically the downforce appears to be on the short end of an unbalanced see-saw while the aero drag is on the long end.

So for every 5kg's of downforce maybe 1kg is seen at the axle? Vs the aero drag where at least every bit of the force generated goes into rotating the swingarm.

So it must be about cooling the tyre.......or is it? The rotational force wanting to push the swingarm up also means there will be a force wanting to pull the rest of the bike down as it all tries to rotate around the swingarm pivot. So I'm thinking the combined effect will be to create anti-wheelie, with a slight loss of downforce on the rear tyre which is offset by better cooling on the tyre.

As for the appeal, that is all about the other Factories forcing Gigi to explain it all in detail. It is a win win: the either have the devices banned or Gigi helps them get up to speed.

that Ducati and its sponsor are just happy that everybody is talking about them. It only costs some small pieces of carbon fibre to be the talk of the day and buy an image of the smartest of the class. Maybe it even adds nothing to performance

Ducati have been focused on mid turn characteristics. Also tire preservation. With Michelin tires the rear is sticking SO well that it pushes the front a bit early in the race. Mid race the bike is behaving well. Then tires drop off late race.

Could this both cool the tire they are loading w all that drive power, AND provide a touch of lift at speed to help w turning faster corners?
(And, legal since no downforce)

I was just imagining the position of the front wheel "spat" at full lean. Could it be that it is shaped to produce a venturi affect producing downforce on the front which is directed straight down toward the track surface? Maybe not but it's an intriguing idea.

Thanks all.. The upswept exhaust theory, hot gas expulsion is a topic of note. Decades back in a specific theatre of war we used a chemical substance called ammonia perchlorate stuffed into the hollow behind a 155mm artillery projectile to increase range. The idea was that it burned at such a high temperature that it would in effect break the vacuum and turbulence behind the projectile thus favouring the projectiles velocity enormously, hence increasing the range of the weapon system. It worked remarkably well. Apply the principle (not the chemical) to a GP bike and I believe there is more than a little merit supporting Ducati and Honda's exhaust systems. Yamaha's system just blows a lot of hot air out the lower one side of the bike thus swirling around the rear tire. Compact, pretty and neat it is but its just a wastegate appendage rather than a contributer to the overall package. Correct me, but I think Aprillia need to look at this angle too relevant to their lack of top speed. Just another bit of input pertaining to a fascinating topic.